As part of the move to reset the Clang/LLVM stable branches to their new versions, I disabled the compiler_crashers/28616-swift-parser-parseexprsequence-swift-diag-bool-bool.swift test because it was consistently failing to crash when I ran the tests locally. (It is expected to crash, so the test fails when it does not crash the compiler.) This is very strange because the test system prints out the failing command, and when I run that directly, I always get a crash. I can run it in a debugger and see that it is overflowing the stack.
For some reason, when the test runs from the test harness, it does not crash. Of course I get a ton of diagnostics because the input is invalid, but there is no crash. I tried doubling the number of braces in the test, but that did not help. I also tried to increase my stack size in case the test harness does that, but ulimit had no effect.
I don’t want to leave this test in limbo, but I’m kind of stuck figuring out why it is behaving inconsistently. Any ideas?